Rectification (geometry) - Orders of Rectification

Orders of Rectification

A first order rectification truncates edges down to points. If a polytope is regular, this form is represented by an extended Schläfli symbol notation t₁{p,q,...}.

A second order rectification, or birectification, truncates faces down to points. If regular it has notation t₂{p,q,...}. For polyhedra, a birectification creates a dual polyhedron.

Higher order rectifications can be constructed for higher order polytopes. In general an n-rectification truncates n-faces to points.

If an n-polytope is (n-1)-rectified, its facets are reduced to points and the polytope becomes its dual.